Problem: $ \left(\dfrac{6}{5}\right)^{-3}$
Explanation: $= \left(\dfrac{5}{6}\right)^{3}$ $= \left(\dfrac{5}{6}\right)\cdot\left(\dfrac{5}{6}\right)\cdot \left(\dfrac{5}{6}\right)$ $= \dfrac{25}{36}\cdot\left(\dfrac{5}{6}\right)$ $= \dfrac{125}{216}$